No abstract

The magnetic susceptibilities and microstructures of Zr-Nb binary alloys were investigated to develop a new metallic biomaterial with a low magnetic susceptibility for magnetic resonance imaging (MRI). The magnetic susceptibility was measured with a magnetic susceptibility balance, and the microstructure was evaluated with an X-ray diffractometer (XRD), an optical microscope (OM), and a transmission electron microscope (TEM). Zr-Nb alloys as-cast showed a minimum value of magnetic susceptibility between 3 and 9 mass% Nb, and the value abruptly increased up to 20 mass% Nb, followed by a gradual increase with the increase of the Nb content. XRD, OM, and TEM revealed that the minimum value of the susceptibility was closely related to the appearance of the athermal ! phase in the phase. Since the magnetic susceptibility of Zr-3Nb alloy consisting of an 0 phase was as low as that of Zr-9Nb alloy consisting of the and ! phases, that of the ! phase was lower than that of the 0 and phases. When Zr-16Nb alloy was heat-treated, the isothermal ! phase appeared, and, simultaneously, the magnetic susceptibility decreased. Therefore, the ! phase contributes to the decrease of the magnetic susceptibility, independently of the formation process of the ! phase. The magnetic susceptibility of the Zr-3Nb alloy as-cast was almost one-third that of Ti-6Al-4V alloy, which is commonly used for medical implant devices. Zr-Nb alloys are useful for medical devices used under MRI.

Body ownership can be modulated through illusory visual-tactile integration or visual-motor synchronicity/contingency. Recently, it has been reported that illusory ownership of an invisible body can be induced by illusory visual-tactile integration from a first-person view. We aimed to test whether a similar illusory ownership of the invisible body could be induced by the active method of visual-motor synchronicity and if the illusory invisible body could be experienced in front of and facing away from the observer. Participants observed left and right white gloves and socks in front of them, at a distance of 2 m, in a virtual room through a head-mounted display. The white gloves and socks were synchronized with the observers’ actions. In the experiments, we tested the effect of synchronization, and compared this to a whole-body avatar, measuring self-localization drift. We observed that visual hands and feet were sufficient to induce illusory body ownership, and this effect was as strong as using a whole-body avatar.

No abstract

This article reports the first psychological evidence that the combination of oscillating optic flow and synchronous foot vibration evokes a walking sensation. In this study, we first captured a walker’s first-person-view scenes with footstep timings. Participants observed the naturally oscillating scenes on a head-mounted display with vibrations on their feet and rated walking-related sensations using a Visual Analogue Scale. They perceived stronger sensations of self-motion, walking, leg action, and telepresence from the oscillating visual flow with foot vibrations than with randomized-timing vibrations or without vibrations. The artificial delay of foot vibrations with respect to the scenes diminished the walking-related sensations. These results suggest that the oscillating visual scenes and synchronous foot vibrations are effective for creating virtual walking sensations.